System and method of control for electric motors.



L. G. RILEY. SYSTEM AND METHOD 0F CONTROL FOR ELECTRIC MOTORS.

APPLICATION FILED OCT. 3. ISIS.

NESSES:

Patenfedsept. 28, 1915.4 Fiq. l.

lIII'IIIII II'IIIIIIII F/q. F137 numsramlmunn. lunas-Ll.:

LYNN Gr. RILEY, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR .TO WESTINGHOUSE ELECTRIC ANDv MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

SYSTEM AND METHOD OF CONTRODFOR ELECTRIC IOTORS.

specification of Letters Patent.

Patented Sept. 28, 1915.

Appiict'ipn sieri october 3,1913. serial No. 793,097.

-k To. all whom it may concern 'Beit known that I',.LYNN G. RILEY, a citizen of the United. States, and a resident of lVilkinsbui-g, inthe county of Allegheny --and State of Pennsylvania, have invented a' new and useful Improvement in Systems and s Methods of Control for' Electric Motors, of

'l which the following isa specification.

My' invention relates to systems and methods of lcontrol for electric motors, and it vhas special reference to the -control of electric vehicle motors which are operated yby energy from storage batteries.

desirable surging inthe line when the bat- 'satisfactory and efficient operation.

The object of my invention is to provide a` system and method of control for electric motors, of the class above Indicated, where-e by a l plurality of motoroperating speeds may be,secured,zthe arrangement being suchthat all sections of` the supply batteries are continuously and uniformly dischargedduringxoperation. y

In the prior art, a transition of the sections of supply batteries from a parallel to a series relation has ;usuallydinvolved .an open-circuiting of allor-of aportionof the sections. The first. method results in an untery circuit' is again closed and tlie'second method` imposes an overload on a portion of the batte ry, thereby causing an excessive burning of Contact members andan unequal f amount' of discharge of the several sections,

with the consequent unbalancing of capacity and voltage.

According to my present invention, I pro- @vide a method and means whereby the foregoing disadvantageous features are obviated since, during the abovementioned transition from parallel to series relation, continuous yand evenly-balanced currents are maintained through the sections of batteries. Another advantage is the permissible elimination. of magnetic blowout devices 'by reason of the relatively small current carried by any one battery section.

Variations in the field winding connections are effected in conjunction with the changes in battery connections to produce In the accompanying drawing, Figure 1 is a diagrammatic View of a system of control embodyin'g my invention, a controller of the .drum type being hshownileveloped into a siiigle plane, in a well known manner;

V,tem here shown comprises an electric motor having an armature 1 and field magnet windings 2 and 3, av reversing switch-4, a controller 5 that is adapted to occupy a plural'- ity of motor-operating positions a to e, inclusive; storage battery sections 6 and 7, a bridging resistance 8, a shunting resistance 9, a battery-charging switch l0 and a charging plug l1. v i

The battery-charging switch 10 is a double pole, doublethrow switch and, when thrown to the right, as shown'on the drawing,con nects the storage battery sections 6 and 7 in series relation between the terminals of the charging plug 11. When thrown to the opposite position, the connections of the storage batteries are dependent upon the positions of the controller 5, as hereinafter pointed out.- i

Assuming that-the reversing switch 4 is moved into the position marked Forward and -that the controller is movedv into its positiony a, a connection is established from one terminal Bg-I- of the battery section 6 through a conductor 12, a control finger 13, contact members 14 and 15 and a control finger X, to a junction point 16. A connection is also established from a terminal Bl-lof the battery section 7 through a conductor 17, a switch-blade 18 and a conductor 19 to the junction ypoint 16,\circuit being continued from this point through control fingers XR and A+ on the reversing switch 4 which fingers are bridged by a Contact mene ber 20, a conductor 21, the'motor armature control finger 35, and conductors 3G and 37 to a terminal Blof the battery 7. A connection is also established from the conductor 30 through a conductor 38, a. switch blade 39 and a conductor 40 toa terminal B,- of the battery 6.v Circuit connections V are thus established as shown'in Fig.l 2 of the drawing. If the controlleris now moved to position the terminals B. ',{4 and Bl-i-l of the battery sections are still connected vtothe junction point 16, circuit being continued from. this p`oin t. 'as in position a,

switch .Jr aiidlthe conductor 24 to a junction- '-poiiit one circuitbeing `continued from here through the conductor 25. the field mag-v net winding 2. the condiictoi- 2G. the control l fingerFaanda contact member 42 to the 'tors-lfl. 3l and 32 and thecontrol. finger Fi.- to the contact member 325. Consequently. the field magnet windings Q and 3 are connected iu parallel relation fromthe jiim-,tio'n-point il to the contact-member 33.

The circuit: connections are otherwise the.

saine as before. and, as a result, the arrange- -ment of Fig. ,3 is obtained.

In position B` o't' the controller. the field magnet winding,Y 2 is lopen-circuited by reason ot" the disengagement of the contact member lil-from the'control finger Fa. A new circuit is established from the conductor Z165 which is connected to the terminals Bland Bfofthe battery sections. through .i

conductor 45. the bridging resistance S. a:

conductor lfoa control finger Br and a contact member 47 to the contact member 15. which is coiiii'ected'to` the terminals BH- and 132+ of' the battery sections. The bridging resistance 8 is thereby `connected in parallel relation with the battery sections, and the arrangement of' Fig. 4 is provided.

ln position B. the previously disconnected field magnet winding 2 is connected to the opposite end of the field magnet winding 3 .from that shown in Fig. 3, al circuit being established from the "junction point 41. through the conductor the fieldwind-ing the conductor 26. theI control finger 1173-. a contact member TLS, the contact member QS. the finger F b-fand-the conductor 29 to the field. magnet winding l winding 2 is thus short-circuited by a connection from the junction-point l1. through theconductor .l-, the control finger Fnand bei: QS. v and 33 are disengaged from vtheir respective the contact member 4i to the contact mein- Also the contact members l5. 3i

control fingers, thereby disconnecting the terminals 131+ andvBf# of'the battery secv tions 7 and G, respectively. Jfrom the bridging resistance S. A series relation .of the vbatterysections and thel resistance is thus obtained and the connections of Fig. 5 are established. l

ln position B... the contact member 'il 'ls The field in agnet` 'disengaged from the 'control finger Ffhl y lthereby resistance 8 is thus sliort-circuited. the connections being as shown in Fig. 'i'.

It will-be understood that. throughout the battery transition. as effected b v the connections ot' positions B1. B.. B., and 0. continuous and evenly-balanced currents are .maintained in the several battery sections.

In position (1.'the field magnet windings are again connected in parallel relation. as in Fig; other connections remaining the same. (See Fig. 8.)

In position c. la connection is" established from the conductor 31. through a conductor 50. the shunting resistance 9. a conductor 51, a control fingerS and contact members and 53 to the contact member 2S. By this means. -the shunting resistance 9 and the field windings are all connected in parallel relation. as shown in Fig. 9.

`lt thus appears that a plurality of gradually-increasiiig-'motor speeds are provided by first establishing a low-voltagef'connection Vbetween the battery sections, and .al strong field. The field is then weakened b v connecting the parts of the field magnet windings in parallel relation. T he field windings are next changed ovei to series relation. as at first. and, meanwhile. the transition of the battery sections from parallel to series or'high-voltage connection is accomplished without opeii-circuiting or unequally loading any section'. The field magnet windings are again connected in parallel relation and. for the final speed. the field is weakened by shuntiiig a resistance across the parallel windings. l l,

Variations in thel circuit connections and the arrangements of' the control positions may be effected within the spirit-and scope of my invention. and l desire that only such limitations shall ,be imposed as are indicated in the-appended claims. 't

I claim as niwinvention:

y 1. The methodof transition from a seriesparallel relation of a plurality of energy sources and a plurality of dynamo-electric machine windings to a series i'elatioii thereof' that consists in disconnecting one of said windings, inserting a translating device cross said sources of energy. connecting one winding 'across a portion of' the line. opening certain connections of said sources to disposethem in series with said translating I device. opening the portion ofthe linethat short-circuits one of' said windings and excluding said device.

2. The method ot'transition from aseriessources and a plurality of field magnet windings to a series relation thereof that consists in disconnecting one of Vsaid windings, inserting atranslating device across the common terminals of said sources, connecting said previously disconnected windingacross a relatively short portion of the line, opening connections withv said device at opposite ends of the respective sources, opening the portion of the line that short-circuits said previously disconnected winding andl excluding said. device.

3. The method of controlling an electric motor which is supplied with energy from a plurality of sources initially in parallel and a plurality of the field magnet windings of'which are connecte in parallel that consists in disconnecting one of said-windings, inserting a translating device across the common terminals' of said sources, connecting one of said windings in parallel with a portion'of the line intermediate another of said windings and the armature winding, opening certain connections of said sources to dispose them in series with said device, openingthe portion of the line that shortcircuits one of said field magnet windings and y excluding said device.

4. The method of controlling an electric motor which is supplied with energy from a plurality' of sources initially in parallel and a'. plurality of thev field windings of which arel connected in parallel that consists in-disconnecting one of said windings, inserting a translating device across the common terminals of said sources, connecting vsaid previously disconnected winding in :parallel with a relatively short portion of the line intermediate another of said windings. and the armature winding, opening connections with said translating device` at opposite ends' of the respective sources, opening the portion of the line' that short-circuits said previously disconnected winding kand excluding said device.

ings; sixth, excluding said translating device; and seventh, connecting the field magnet windings in parallel sections.

6. r1`he methodof controlling an electric motor which is supplied with energy from a plurality of batteries that consists in the following steps:L first, ,connecting said batteries in parallel sections and the field magnet windings and the armature in series therewith; second, connecting the field niag- `netv windings in parallel sections; third, disconnecting one of said windings and inserting a resistance across the common terminals of said batteries; fourth, connecting said previously disconnected winding in parallel with a relatively short portion of the line intermediate another cf said windings and the armature winding and. opening connections with said resistance at opposite ends of the respective batteries; fifth, opening the portion of the line that short-'circuits said previously disconnected winding; sixth. excluding said resistance; seventh, connecting the field magnet winding in parallel sections; and eighth, connecting a resistance across said field magnet windings.

7. T he combination with a supply circuit. a translating device, and a plurality of sources of energy and a plurality of' dynamo-electric machine windings connected in series-parallel relation. of circuit connections for successively disconnecting one of said windings, inserting said device across said sources of energy, connecting one winding across a portion of the supply circuit.

` opening certain connections of said sources 5'. The method of' controlling an electric motor which is supplied with energy from a plurality of sources that consists in the follov-ing steps: first, connecting said sources in parallel sections and the lield. magnet 'windings and the armature in series therewith; second, connecting the field magnet windings in lparallel sections; third, disconnecting one of said windingsand inserting a translating device across the common terminals ofl said sources; fourth, connecting one et' said windings in parallel with a portion of the line intermediate another of said windings and the armature winding and opening certain connections of said sources to dispose them in series with said device; fifth, opening the portion of the line that short-circuits one of said field magnet windto dispose them in series with said device. opening the portion of the supply'circuit that short-circuits one of said windings, and excluding s aid device.

S. The combination with a supplyfcircuit. a resistor, and a `plurality of batteries and a plurality of' motor field windings initially connected in series-parallel relation, of circuit connections for successively disconnecting one of said windings. inserting said resistor across the common terminals oi said batteries, .connecting said previously disconnected winding in parallel with a relatively short portion of the supply circuit. opening connections with said resistor at opposite ends of the respective batteries. opening the portion of the supply circuit that short-circuits said previously disconnected winding, and excluding said resistor.

In testimony whereof, 1 have hereunto subscribed my naine this 29th day of Sept., 1913.

LYNN G. RILEY.

Vitnesses 'z G.' R. IRWIN, B. B. HINEs. 

